This issue has been partially fixed by Kostas' changeset here (http://hg.savannah.gnu.org/hgweb/octave/rev/daad312c8af0). A single patch object now correctly displays a legend. However, the first example in this bug report, scatter (), still fails. The issue is probably connected with hggroups. Interestingly, both bar graphs and pie charts, which also use hggroups, do work.